Activity of purified plasma FXIII of different Val34Leu genotype as the function of thrombin concentration during the activation period.

Purified plasma FXIII was activated by thrombin for 5 minutes at 37°C. Thrombin was blocked by hirudin, and FXIII activity was measured by the UV spectrophotometric method. Experiments were carried out with wild-type (Val/Val, ■——■), heterozygous (Val/Leu, ┘ · · · · · · · ┘), and homozygous (Leu/Leu, ▪- - -▪) plasma FXIII.